Technical Field
The present invention relates to an antireflection film that restrains reflection of light in a range from visible light to near-infrared light, an optical element including the antireflection film, and an ophthalmology apparatus including the optical element.
Description of Related Art
It is conventionally known that an antireflection film is provided on a surface of an optical element such as a lens to reduce reflection of incident light. As such an antireflection film, a technology that a layer of MgF2 is laminated on the outermost side of the antireflection film is disclosed (see, for example, JP2009-8901A and JP2007-333806A).
However, an antireflection film described in JP2009-8901A or JP2007-333806A has a characteristic of low reflectivity in visible light of about 350 nm to 700 nm, but JP2009-8901 A and JP2007-333806 A do not disclose reflectivity in a wide band from a visible light range to a near-infrared range. In addition, in the antireflection film, a phenomenon that the incident light is attenuated may occur depending on a combination of film materials. There are possibilities that the phenomenon prevents the antireflection film from having sufficient antireflection effect and influences the productivity of the antireflection film and optical parts.